The ultimate objective of our research is the development of S+ME: next generation software for handling measurement error. This research will make fundamental contributions to the conduct of public health studies by developing mature methodology and user-friendly software for handling measurement error. Currently, there is little or no commercial software in this area. The aim of the proposed research is to overcome this deficiency and extend the benefits of measurement error models to a wide audience of biomedical analysts and practitioners. To achieve this aim, much of our research effort will be devoted towards developing regression calibration and iterative imputation methods, two common measurement error methods, in a software package. This methodology will be matured by incorporating diagnostic techniques, sensitivity analyses, and graphical methods into the package. The S+ME module will be implemented as an object-oriented software module in the S-Plus language. A comprehensive case study guidebook will be developed involving real problems with measurement error in exposures and risk factors. PROPOSED COMMERCIAL APPLICATION S+ME will result in an add-on module to the S-Plus software system. This module will be attractive to the existing S-Plus user base as well as the much broader community of biomedical researchers and data analysts. This research will also lead to the development of short courses, books, videos and other educational material.